The answer is to prevent further damage and contain the incident. Isolating a compromised system from the network immediately stops all communication with other hosts, which blocks the attacker from moving laterally, exfiltrating data, or deploying additional malware, thereby limiting the blast radius and halting ongoing harm. On the CISA exam, this concept tests your understanding of containment as a critical phase in the incident response process, often appearing in scenario-based questions where you must choose the first action to take after detection. A common trap is confusing isolation with eradication or recovery—remember, isolation is about stopping the bleed, not fixing the system. Memory tip: think “cut the cord, stop the spread.”
CISA Protection of Information Assets Practice Question
This CISA practice question tests your understanding of protection of information assets. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
During an incident response, the IT team isolates a compromised system from the network. Which of the following is the primary purpose of this action?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "primary"
Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
To prevent further damage and contain the incident.
Isolating a compromised system from the network (e.g., by disconnecting the Ethernet cable, disabling the switch port, or applying a host-based firewall rule to drop all traffic) immediately stops the system from communicating with other hosts. This containment action prevents the attacker from moving laterally, exfiltrating data, or deploying additional malware, thereby limiting the blast radius and stopping ongoing damage.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
To preserve evidence for forensic analysis.
Why it's wrong here
While isolation can help preserve evidence, the primary purpose is containment.
✗
To allow the system to be patched offline.
Why it's wrong here
Patching is a remediation step, not the primary purpose of immediate isolation.
✗
To comply with regulatory requirements.
Why it's wrong here
Compliance may be a driver, but the immediate goal is containment.
✓
To prevent further damage and contain the incident.
Why this is correct
Correct. Isolation contains the threat and reduces impact.
Clue confirmation
The clue word "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse 'preserving evidence' (a forensic goal) with 'containing the incident' (the immediate operational goal), leading them to choose Option A even though isolation is primarily about stopping the attack, not about evidence handling.
Detailed technical explanation
How to think about this question
Under the hood, isolation can be performed at multiple layers: at Layer 2 by disabling the switch port (e.g., 'shutdown' on a Cisco switch interface) or at Layer 3 by applying an ACL that denies all traffic to/from the host's IP. In a real-world ransomware incident, isolating the system immediately stops the encryption process from spreading to network shares via SMB, which is critical because many ransomware variants use PsExec or WMI to propagate laterally within seconds of initial compromise.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Protection of Information Assets — This question tests Protection of Information Assets — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: To prevent further damage and contain the incident. — Isolating a compromised system from the network (e.g., by disconnecting the Ethernet cable, disabling the switch port, or applying a host-based firewall rule to drop all traffic) immediately stops the system from communicating with other hosts. This containment action prevents the attacker from moving laterally, exfiltrating data, or deploying additional malware, thereby limiting the blast radius and stopping ongoing damage.
What should I do if I get this CISA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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This CISA practice question is part of Courseiva's free ISACA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CISA exam.
Question Discussion
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